Investigation of electrolyte and auxiliary anode effects in Electrochemical Discharge Machining of equiatomic AlCrCuFeNi high-entropy alloy

This study investigates the electrochemical discharge machining (ECDM) performance of a newly cast equiatomic AlCrCuFeNi high-entropy alloy, targeted for demanding applications like aerospace, nuclear, marine and defense components. The alloy was synthesized using vacuum induction melting and characterized using SEM, EDS and FTIR in order to confirm compositional uniformity and passive film formation. A sodium nitrate based electrolyte system (C1) was procedurally modified using borax (C2), sodium lauryl sulfate (SLS) (C3) and cetyltrimethylammonium bromide (CTAB) (C4) to analyze the influence of buffering and surfactant chemistry on gas film stability, material removal (MR) and tool wear (TW). A Taguchi L16 design integrated voltage, duty cycle, electrolyte type, auxiliary anode material and auxiliary anode position. The C1 electrolyte under 110 V and 70% duty cycle with copper auxiliary electrode, placed in right position to the workpiece achieved a maximum MR of 38 mg with controlled TW of 7 mg. Electrolyte chemistry emerged as the dominant factor for both MR (Δ = 17.42) and TW (Δ = 11.13). Grey Relational Analysis (GRA) validated the optimized condition, confirming a balanced enhancement of productivity and tool life. The proposed strategy offers a sustainable ECDM framework for machining advanced heat-entropy alloys.